Supporting plates (disks) for filters are known in differing forms and are technically used since a long time. Such supporting plates have the effect, that a filter, placed in a fluid stream essentially basically perpendicular to the stream direction is secured and supported by the plate, so that the position of the filter is even then unchanged, when the fluid to be filtered, for instance a liquid or a molten polymeric material, passes the filter with a high flow speed.
It is a known arrangement in filter devices, in particular for the filtration of molten polymeric material, that they contain in the flow direction of the fluid to be filtered a supporting plate, a filter adjacent to the supporting plate, which filter is itself in direct contact with a filter distance plate, whereby usually a perforated plate is assigned to this filter-sandwich, constituting a support arrangement with the result, that the filter sandwich is secured safely in the fluid stream during the filtration procedure of the fluid. with particles separated from the fluid, by diverting the direction of the fluid stream by appropriate guidance or control elements in such a manner, that the fluid stream passes the filter device in the reverse direction. In this manner the fluid stream first passes the perforated plate, then the distance plate and hereafter the supporting plate, whereby the filter is secured in its position by the supporting plate in this reversible flow position as well. It is further a known method to regenerate the known filter devices, in particular such filter devices which are arranged as described before, when such filters are covered.
The filter devices known in the art and described above, contain a large number of holes, whereby these holes are shaped as cylindrical bores in the about 2 mm to about 15 mm thick support plate.
It is a special disadvantage of the known supporting plate, that the filter is clogged quickly in particular in the region of the holes by filtered-off particles, which requires a regeneration of the filter after a fairly short time of exposure.